I've joined RootsChat as my grandfather was also a director of this company, handling their accounts, and I've just Googled it from curiosity. His name was James Albert Ryder. He retired circa 1961 and died shortly afterwards, unfortunately during my boyhood.
I was brought up in my grandparents' home, and I do seem to remember him referring to a Mr Sullis on occasion, though I'm afraid my mother's and grandfather's work conversation when they got home caused me to instantly switch off.
My grandfather used to be given a lift home from work by a Mr Wink, or someone he referred to as Wink, possibly a nickname? My grandfather's brother, Jack Ryder, was in charge of Robert Davie Seniors works, though I only met him briefly once.